Thallium I complexes

The synthesis and characterization of the monomeric amidinato-indium(I) and thallium(I) complexes [Bu C(NAr)2]M[But(NAr(NHAr)] (M = In, Tl Ar = 2,6-Pr2CgH3) have been reported. Both compounds were isolated as pale yellow crystals in 72-74% yield. These complexes, in which the metal center is chelated by the amidinate ligand in an N, j -arene-fashion (Scheme 33), can be considered as isomers of four-membered Group 13 metal(I) carbene analogs. Theoretical studies have compared the relative energies of both isomeric forms of a model compound, In[HC(NPh)2]. ... 

Thallium complexes amidines, 205 phthalocyanines, 863 porphyrins, 821 triazines, 205 Thallium(I) complexes... 

A thallium(I) /3-diketiminate, [HC (Me)C(C6H3-2,6-Me2)N 2]Tl, and its use in the preparation of copper(I) complexes are reported. " No structural data are available on this compound. Thallium(I) complexes of 1,3-diphenyltriazenide and 1,5-di-/)-tolylpentaazadienes have been synthesized and structurally characterized. 

A tris(imidazolyl)borate (138) complex of thallium(I) has been synthesized.The solid-state structure of hydrotris(imidazolyl)boratothallium(I) consists of one-dimensional, twisted, ladderlike strands, and three-coordinate thallium centers. Due to the position of the nitrogen donors, the tris(imidazolyl)borate ligand is not capable of forming metal chelates as are observed in tris(pyrazolyl)borates. Poly(benzotriazolyl)borate ligands have some features of both tris(pyrazo-lyl)borate and tris(imidazolyl)borate systems. Thallium(I) complexes of bis-, tris-, and tetrakis (benzotriazolyl)borates are reported. These adducts have been synthesized by treating the corresponding potassium derivative with an equimolar quantity of thallium(I) formate. ... 

Even if many of the stability constants of thallium(I) complexes in aqueous solution have been determined before the time period covered by this review (58), a selection of constants is presented in Table I (59-68), since they are of interest for investigating several other properties of thallium(I) complexes (see, for example. Sections III,A, IV,A,1, and V). Most of the known stability constants for the complexes of... 

Overall Stability Constants for Thallium(I) Complexes in Aqueous Solution at 25°C ... 

As a consequence, it is not surprising that there appears to be only one isolated structure claimed. This is of the indium(I) and thallium(I) complexes with a single M—C bond from a o--bonded benzene anion that carries two bulky tri-substituted benzene substituents in ortho positions these partially block approach of other potential donors to the metal cation (Figure 4.3). An X-ray crystal structure has been determined, defining the shape. It is a rare observation, as other complexes (such as Mn(I) and Fe(I)) of the same ligand bind another ligand at the open side of the molecule, as expected. In any case, this coordination number is trivial in the sense that it can have only one shape - a linear M—L arrangement. 

Several attempts have been made to replace silver ion with ions of other elements [74, 75]. Of particular practical and theoretical interest is the possibility of using thallium salts [74]. The physical and chemical properties of silver(I) and thallium(I) compounds are similar. Thallium(I) salts are stable up to 150°C in the absence of oxygen, but thallium(I) complexes with unsaturated hydrocarbons have not been studied before. The results of the separation are given in Table 6.1 [74]. 

The synthesis and characterization of a thallium (I) triscar-bene complex has been described. The reaction of a chelating tripodal carbene ligand l,3,5- tris(3-terf-butylimidazol-2-ylideno)methyl -2,4,6-trimethylbenzene with Tl(OTf) resulted in the formation of the triscarbene thallium (I) complex (55). An X-ray structural determination showed that the tripodal carbene ligand coordinates with the thal-lium(I) ion in (55) in the expected tridentate conformation. 

Table VIIL The Stability Constants and Absorption Spectra of Some Thallium (I) Complexes at Ionic Strength 0.075"...

Thallium complexes amidines, 205 phthalocyanines, 863 porphyrins, 821 triazines, 205 Thallium(I) complexes hexafluoroacetylacetone, 372 Thallium III) complexes carboxylic acids reactions, 443 1,3-diketones synthesis, 377... 

Barbera et al. prepared a series of thallium(I) complexes, in which the position and number of side chains were changed systematically ((58) M = Tl). A minimum of four chains was required to induce mesomorphism in these systems (Table 37), and on the basis of X-ray diffraction, the monotropic mesophases were identified as Colii. The formation of the columns was due to the association of these half-disk compounds into dimers, and to their subsequent stacking. The dimeric nature of these thallium(I) complexes was confirmed by the analysis of the single-crystal structure of the non-mesomorphic dimethoxy analog. In the crystalline phase, the co-planar... 

Jones et al. also prepared and structurally characterized thalliimi trichloride-NHC complexes [154]. Shortly thereafter, Meyer prepared and characterized a triscarbene thallium(I) complex (Figure 15.29) containing the tripodal ligand 1,3,5-[tris(3-tert-butylimidazol-2-ylideno)methyl]-2,4,6-trimethylbenzene [155]. To date these are the only reported examples of thallium-NHC complexes. 

Several diketonate thallium(I) complexes with a different number of alkoxy groups on the aromatic ring have been synthesized [79]. The mesogenic behavior of the thalli-um(I) and of the copper(II) derivatives are qualitatively similar. The authors propose a dimer structure. 

The IR spectrum of the thallium(I) complex containing the ligand pivaloylcyanoformaldoximate, 0NC(CN)C(0)CMe3 (L ), TI3L3, shows that T1 is coordinated by CN, NO and CO groups of the ligand. 

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